Thame are suddenly looking in danger of missing out on promotion after they slipped to a second consecutive home defeat in Ryman League Division 1 on Saturday.
The home side exerted early pressure as they looked to put last week's defeat by Walton & Hersham behind them.
Paul Riordan produced a great save in the 17th minute to deny Greg Williams, but he was powerless to prevent Thame from going ahead a minute later.
A slick move found John Mitchell in space and his pass was fired home from ten yards out by Mick Swaysland.
The lead lasted only three minutes. Mark Jones waited for the ball to run out of play, but Scott Fitzgerald didn't give it up and crossed for Ant Cross to hammer past Ian Moores from close range.
Riorden was the busier of the two keepers in the second half, saving a Mark Jones header and seeing efforts from Minton and Swaysland go just wide.
But in the 69th minute, the visitors got a decisive second goal.
Thame were slow to react to a short corner and the resulting cross caused havoc as Yaku beat Moores to the ball, and in the resulting scramble Gary Williams fired home.
In the final minute, West burst through on goal only to be brought down from behind by Maric Buchanan in the penalty area, but to the home side's frustration the referee waved play on.
Thame: Moores, Jones, William, Bradley (Potter 65), Brown Avery, Merritt, West, Swaysland (Smith 85), Perna, Mitchell (Minton 45).
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article